We present the final and full data release for the Apertif Radio Transient System (ARTS), a supercomputing radio-telescope instrument that performed real-time Fast Radio Bursts detection and localisation on the Westerbork Synthesis Radio Telescope (WSRT) interferometer. The release includes the downsampled time-domain data from all pointings, obtained from 2019-2022. The 2019 data was released before, as Apertif Time-Domain Data Release 1, and is included here again. This snapshot of the fast-transient sky can be interesting for validation and searching for pulsars and Fast Radio Bursts. For details on observing and data, see van Leeuwen, J. et al. “The Apertif Radio Transient System (ARTS): Design, Commissioning, Data Release, and Detection of the first 5 Fast Radio Bursts”, 2023, A&A 672, A117 (hereafter: van Leeuwen et al. 2023). The analysis of the full/DR2 sample is presented in Pastor-Marazuela, I. et al. "Comprehensive analysis of the Apertif Fast Radio Burst sample: similarities with young, energetic neutron stars" 2024 A&A (submitted).

All raw downsampled observational data from the time-domain survey are released. The data are 1-bit Stokes-I PSRFITS files. Data from before 2020 May 1 supply 384 channels of 0.8MHz each, with a time resolution of 2.048 ms. Later data are archived using higher temporal and spectral resolution, and provide 768 channels of 0.4MHz each, every 0.8 ms. A full overview of the observations & processing (Fig. 1) can be found in van Leeuwen et al. (2023).  Archive data for pointings towards all FRBs presented in Pastor-Marazuela et al. (2024) are directly accessible. For other pointings the metadata is directly available, but the data itself first needs to be staged from tape. Access to that data can be requested via the helpdesk.

For a detailed description of the Compound-beam and Tied-array-beam Sensitivity, and of the RFI, see Sect. 7 of van Leeuwen et al. (2023). The five FRBs presented in that paper were discovered in raw, high-resolution data, but are also visible in this archived data (Fig. 2).

Raw, down-sampled pointings

The time-domain data are in PSRFITS format, with 1-bit sampling. The data are total intensity (Stokes I). For each pointing, all TABs are available. Data from before 2020 May 1 supply 384 channels of 0.8MHz each, with a time resolution instead of 2.048ms. Later data are archived using higher temporal and spectral resolution, and provide 768 channels of 0.4MHz each, every 0.8ms.

The Apertif Time-Domain Data Release 2 (ARTS DR2) is hosted on the Apertif Long Term Archive and exposed to the community through the standard Virtual Observatory protocol. This section describes how the data products can be queried and accessed by using different applications.

User Interfaces

The science-ready data products are exposed through standard Virtual Observatory protocols to facilitate their access and exploration.

We recommend astronomers use the VO interfaces for data discovery. The data published in the VO can be accessed using a web browser at https://vo.astron.nl (how to access the data can be found here). Details on other protocols are listed below. These interfaces will redirect to ALTA file servers for data access where appropriate. ALTA is the Apertif Long Term Archive system.

In particular, the protocols offered are the Tabular Access Protocol (TAP), Simple Application Messaging Protocol (SAMP) and the Simple Image Access protocol (SIA). TAP and SAMP enables queries to explore the data in a tabular form using tools such as TOPCAT. TOPCAT is an interactive graphical viewer and editor for tabular data, it enables the interactive exploration of large tables performing several types of plotting, statistics, editing and visualization of tables. SIA enables the rapid display of images and cubes through all sky atlas tools such as ALADIN. ALADIN is an interactive sky atlas allowing the user to visualize digitized astronomical images/cubes and superimpose entries from astronomical catalogues or databases.

Data Usage Policy